Help with splitting mesh

I need help with splitting a 3d mesh.

I have a 3d object thats displayed using triangles. What Id like to do is split my mesh
into a new mesh but it should be halved with the
hole left by the splitting now closed when rendering. The object is centered at 0,0,0
and orientated at the correct position.
Is the an OpenGL function that can do this or do
I have to do it manually. If the latter is true id like some help aswell. Appreciate it.

CIAO

What Id like to do is split my mesh
into a new mesh but it should be halved with the
hole left by the splitting now closed when rendering.
Do you mean you want to split an arbitrary mesh (possibly nonconvex) in half, so that each part after the split is sealed?

Opengl has no such functions for this task, but it does have user clip planes. I don’t think that’s what you want. And just to cover my arse, there may be a convoluted way of doing this with some fancy shader stuff, but I’m not going there. And there is some CSG stuff that is possible, but I’m not going there either.

I think you probably want to post this question in the math & algos forum. This is very doable and not all that difficult depending on what you are dealing with.